This was a very good series. StarFist series of course takes place in the future and revolves around a future version of a MEU(Marine Expeditionary Unit) there are 14 books in the series so they should keep you busy.

Baen Books has the first Honor Harrington for free as well as a few others.baen.com/library/books.aspI've popped them on my Kindle Fire HD with no problems. See the Reader Software button on the list on the left.This is apparently almost impossible according to many reviewers of the Kindle Fire. I can only assume they are illiterate or stupid.edit: bsrlee beat me to it.

Elizabeth Moon's Vatta War series and Herrano series are both good, and should be available in e-book format.I'll echo the Lost Fleet series by Jack Campbell as also solid.I thoroughly enjoyed R.M. Meluch's Tour of the USS Merrimack series, which combines ship and marine combat with some fun plot and setting ideas.Mike Shepherd's Kris Longknife series also hops around from space to ground combat and are good reads.I did enjoy John Ringo's Troy Rising series. It's very near future, with a twist (in fact, it's clearly meant to be the beginnings of Howard Taylor's Schlockiverse from the Schlock Mercenary web comic which is itself a very good SF military series, which you could read on a Kindle, I believe— schlockmercenary.com). He does get technical on the science/engineering side in places, but with giant solar space lasers, a poor-man's Death Star made from an inflated, hollowed-out asteroid, and an interstellar war started over a breakfast condiment, what do you really care?

I would also recommend "the Lost Fleet". The "Death's Heads" series is really good too. Written by David Gunn I think 3-4 books are available now and they center around an antihero. I got them on my nook, so you should have no problems finding them for the kindle!